H.R.H. Don Francesco Nicola Roberto Paternò Castello e Guttadauro Ayerbe Aragona is the current head of the Royal House that ruled over the ancient kingdom of Aragon which at its peak spanned from the north-eastern Iberian peninsula to the Aegean sea. Explore the site to learn more of this ancient noble house and the recognized claims of this family.

As a recognized legitimate fons honorum, the House of Paternò has introduced new or re-established its hereditary rights to the grand mastership of orders of chivalry, chief of which is the Military Order of the Collar of St. Agatha.